Class-D amplifiers can be used in consumer and automotive devices to achieve good signal quality, high output power, high efficiency and long-term battery life for mobile or automotive applications. For example, class-D amplifiers can be used in personal computing devices such as mobile phones, hearing aids, and audio systems such as home theatre systems, power speakers, subwoofers, and bass amplifiers.
A class-D amplifier typically includes a driver device to generate a driving signal for power transistors in the power stage of the class-D amplifier. Conventional driver devices for power stages of class-D amplifiers generally require bootstrap capacitors or a charge pump voltage for producing a reference voltage. In addition, conventional driver devices for power stages of class-D amplifiers typically have stringent capacitance requirement for transistors in driver devices. Consequently, the component cost of a conventional driver device can be substantially high.